Hey all... I was wondering if today's CJ-4 HDEO lubes have enough anti-wear additives to protect older engines with flat tappet cams? I know that the CJ-4 HDEO's have reduced amounts of certain additives compared to older CI-4 version. I got asked this question today by a friend who has an older muscle car with a flat tappet motor. He was told that he should still run a ZDDP additive with a current CJ-4 lube if he chooses to run a diesel motor oil. Are CI-4 oils even available anymore besides from Amsoil?

Should be penty unless it has super stiff valvesprings like a 375hp 396.regular pcmo is fine for a stock engine. Theres millions of engines...jeeps,chevys etc running around on sn oil and the owner does not know a thing about oils and they are not eating cams

Lucas oil still makes a CI4+ oil. As for the ability of CJ-4 oil to protect flat lifter cams, it seems that if you have stock cams, or cams not built for performance, CJ-4 is more than strong enough to protect those cams.

Thanks guys.. I believe it is a late 60's 396 motor with stiffer springs and bigger cam? He had mentioned to me also that he wasn't sure if a high viscosity oil such as 20w50 was needed or not? I did not know how to answer that..as I have no experience running older big block chevy's. I would think personally that any current 15w40 CJ-4 oil would do very well. Im not sure a HDEO 10w30 would suffice in this application? I know regarding older motors that bearing clearances and such are far larger/looser than today's engines.

I would think a CJ-4 would be adequate. Nonetheless, you should still be able to find some CI-4 and CI-4+ lubes out there. Up here, it's a little hard, and Imperial Oil yanked all the old stuff. The data sheets for them still exist at XOM in the U.S. though, for what it's worth.

As you're aware, there are other choices from Amsoil, along with RP XPS and Valvoline VR1 and Defy.

15W-40 CJ-4 is perfect, CJ-4 having typically 1000 ppm P (phosphorus of ZDDP), 1200 ppm P being the maximum limit. They also have other antiwear additives in the mix, such as moly, which greatly increase the potency of ZDDP.

The tests for CI-4 (or CI-4 Plus) are less stringent on wear than for CJ-4, despite CI-4 (Plus) having no ZDDP limit. So, you're better off with CJ-4 than CI-4 (Plus) if you're given the choice. ZDDP is not the entire story when it comes to wear. ZDDP is necessary for wear protection but it doesn't work well in protecting against wear while used alone and the other additives can make a big difference. So, it's more the balance of ZDDP and other additives.

I would recommend Mobil Delvac 1300 Super 15W-40. If cold starts are a problem in your area (temperatures below 10 F), use a 5W-40. (For 5W-40, Rotella and Delo are cheap and Mobil 1 Turbo-Diesel Truck is also a good option.) 5W-40 is thinner (HTHS viscosity ~ 3.7 cP vs ~ 4.3 cP for 15W-40) and will wear your flat tappets more than 15W-40 but it should still be acceptable. Don't use 10W-30 CJ-4 for your flat-tappet application if you're concerned about wear. Thicker oil is better for boundary lubrication (metal-to-metal contact), such as for the lubrication of flat tappets or other wear-prone valvetrain systems.

Yes, CI-4 or CJ-4 oils are fine. CJ-4 limits the ZDDP, and with some of the early versions, this might not have been great, but they have matured and are fine.

DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

Viscosity: Stay with the viscosity originally recommended by the manufacturer. IF it was 15W-40, I'd go to 5W-40 in most cases, especially if morning temperatures are below 50ºF. If you are going to race it high rpm's and high temp, you can go with a 5W-50. My Corvair originally called for 10W-30, which I was using, but I went to 5W-40 when I was planning on a long summer trip through an area here where normal ambient temperatures are over 120ºF, which will not do much to keep an air cooled engine in the 100º range.

If stiffer springs so it needs more zddp, just dope some in. You won't need a lot. Thing is, I'd do a voa before actually coming up with a treat rate to ensure that what you're doing is Ok. Don't want to dope anything too high.

Something like the redline assembly lube should do the trick. There are also zddp replacements...

My recent Schaeffer 15w40 syn blend CJ-4 had 1429 zinc, 1104 Phosphorus, 1161 Calcium, and 46 moly after 13733 miles on the oil. Haven't done a virgin analysis on it. I have been told by Schaeffer that their 5w40 full syn CJ-4 has the same add pack anti wear stuff as this one.

DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

I agree on this.

Flat tappets require extreme-pressure (= antiscore) additives such as moly more than ZDDP, which is not an antiscore but an antiwear additive. So, what you really need is an oil with a good balance of ZDDP and moly. I don't think too much moly makes too much of an harm other than more engine deposits but too much ZDDP will certainly result in less protection against wear after a certain optimum value of ZDDP. This could be as high as 2500 ppm P but don't take chances with aftermarket additives. There are also different types of ZDDP and the one used in your oil is optimized against other additives.

Once again, my recommendation for temperatures above 20 F is Mobil Delvac 1300 Super 15W-40, which has about 1000 ppm P and also has the extremely potent trinuclear moly. For lower cold-start temperatures, use Mobil 1 Turbo-Diesel Truck 5W-40 if you want premium protection. A cheaper alternative would be Rotella 5W-40, and an even cheaper alternative would be Delo 5W-40.

DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

I agree on this.

Flat tappets require extreme-pressure (= antiscore) additives such as moly more than ZDDP, which is not an antiscore but an antiwear additive. So, what you really need is an oil with a good balance of ZDDP and moly. I don't think too much moly makes too much of an harm other than more engine deposits but too much ZDDP will certainly result in less protection against wear after a certain optimum value of ZDDP. This could be as high as 2500 ppm P but don't take chances with aftermarket additives. There are also different types of ZDDP and the one used in your oil is optimized against other additives.

Once again, my recommendation for temperatures above 20 F is Mobil Delvac 1300 Super 15W-40, which has about 1000 ppm P and also has the extremely potent trinuclear moly. For lower cold-start temperatures, use Mobil 1 Turbo-Diesel Truck 5W-40 if you want premium protection. A cheaper alternative would be Rotella 5W-40, and an even cheaper alternative would be Delo 5W-40.

Also note that Non-ILSAC (non-GF-5) SN oils are exempt from the 800 ppm P ZDDP maximum limit. This means xW-40 and xW-50 SN oils have no ZDDP maximum limit. Also, high-mileage SN oils of any viscosity have no ZDDP maximum limit, as they are not GF-5. ZDDP maximum limit is imposed by the "Resource Conserving" (of the GF-5) designation, not the SN designation by itself.

This said, Mobil 1 0W-40 SN is a great alternative for flat-tappet engines. It has about 1000 ppm P (of ZDDP), which is similar to CJ-4 oils, and (probably) has trinuclear moly, the most potent kind of moly. It also has another advantage against CJ-4 oils: It's tailored more toward gasoline engines. This is unlike CJ-4 oils, which are tailored more toward diesel engines.